Help understanding this sentence/joke

Question

For context, the girl has found out that her 推しメン(refers to someone's favourite member e.g. of a idol group from what I understand) has been exposed (週刊誌にすっぱ抜かれて). Based on the context below it would seem that they were caught at a love hotel, which If I understand the way the quotes are being used is called フリーバッティング(why would a love hotel be called this).

However, I am looking at the second part of the sentence and am not quite sure I understand what is being said. If I understand correctly it is essentially saying something like: if you are going to play around with women, then at least 'narrow down to a low and inside pitch, and swing'. Is this essentially saying something like "focus on one woman"(i.e. don't play around with multiple women), or am I completely off in my understanding? There is no more context as this was only a short few lines as the character was leaving the classroom.

「何よラブホテル『フリーバッティング』って、どうせ女遊びするなら内角低めの直球に絞って振りなさいよ」

なんか、独特な愚痴をこぼしている

Answer 1

You’ve got the basic baseball metaphor right – the speaker is implicitly comparing the idol to a batter who swung at the wrong kind of pitch. I’ll break down a few of the key phrases below.

フリーバッティング (“free batting”)

means batting practice, and according to 大辞林 it refers specifically to a type of practice in which the batter is allowed to pick what kind of pitch he wants. I initially took this as the speaker's own metaphor for the idol's philandering, but on reflection I think you're correct in interpreting it as the name of the love hotel where he was caught. Presumably, it's this name that then inspires the speaker to come up with the baseball metaphor that follows.

[狙{ねら}い球{だま}に] 絞{しぼ}って振る

refers to batting selectively or “waiting for the right pitch" – that is, planning one's at-bat and taking a careful, disciplined approach, rather than simply chasing any pitch that comes along or trying to decide after a pitch is thrown whether it is going to be hittable or not. The "right pitch" can vary depending on the state of play, the pitcher's strengths and weaknesses and pitching patterns, and the batter's objective (e.g., getting on base vs. hitting a sacrifice fly or bunt). It can also change during the course of an at-bat.

内角低めの直球

is a hypothetical example of a 狙い球 – a low, inside "straight" pitch. (That is, a non-breaking pitch, like a four-seam fastball, as opposed to a curveball or a slider.)

So we can translate this part of the passage as

A love hotel called "Free Batting"? Give me a break! If you’re going to fool around, don’t just swing at anything – wait for a non-breaking pitch that’s low and inside.

Without more context, I don't think it's possible to say exactly what is meant by this metaphor, or whether there’s any real significance to the specific pitch that’s named. But the basic idea seems to be that the guy should have been more selective in choosing a partner and/or a venue for his philandering. That is, either the woman herself was somehow unsuitable, or he should have taken her somewhere other than a love hotel. And possibly these two ideas are linked: He shouldn’t be fooling around with the kind of woman who is content to be taken to a love hotel.

Answer 2

I looked up 内角低め and found this:

https://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1269920047

In baseball, there are two types of pitches, wide-angle (外角) and narrow-angle (内角). Narrow-angle shots are arguably harder to hit because they fly very close to the batter's body so you have to twist your body to reach the ball.

So essentially, what the speaker means by 内角低めのストレート（直球）を振る is to throw a pitch that is hard to hit. In this case it's very similar to the meaning of the English expression "throwing a curveball".

In contrast, フリーバッティング is a 和製英語 that means "batting practice". In batting practice, the ball is easy to hit because it's usually done by a machine that throws balls with a predictable trajectory.

Using this as a metaphor, the complaint is essentially saying that by going to a love hotel to mess around, he was making it too easy for the media to expose him. What is implicitly understood here is that it is not uncommon for idol group members to play with women. However, this person seemingly made no efforts to be discreet, choosing a location as public as a love hotel to carry out his deed, which is why the fan was frustrated.

Translating the whole sentence, we have:

What is he thinking going to a love hotel, that's like letting a batter off the hook with free shots. If you're going to do something risky like play with women, at least throw a curveball (make it harder for them to find out, be discreet about it).

Answer 3

The last line looks like the narrator's thought in response to the person speaking. The narrator thinks "What weird complaint this guy has".

Free-batting does not seem to be the name of the love hotel. ってworks like は; it brings up a topic. The second half of the sentence is necessarily about that topic. The second half of the sentence is not about a specific hotel, but about how to treat?/chase?/interact with? women (in baseball analogy form, and I don't get the analogy). So free-batting is some way of chasing women, or some activity.