I need to talk to my boyfriend about something but I dont know how?

Girls have to wear leggings to the gym, that's unavoidable... why does he care if guys look at you? you aren't revealing yourself or talking to anyone as if you're single so really there's no harm. Sports bras aren't even bras anymore, they're so decorated and well designed that some girls will just workout without a shirt on. In the end you are the person dressing yourself in the morning, not your boyfriend. He makes you think he wants the best for you, but really I can tell he's insecure about himself and doesn't trust you fully if someone were to ask you on a date. Don't let him tell you what to wear if you're happy, there's some deeper issues here and i think u should talk to him about how this makes you feel and why it's hurting your relationship with him

He is not doing it out of love he does not trust you there is nothing you can say that will change him and there is no need to be self conscious he must love you as you are if he wants you to change he does not love you at all its tome to move on fibd someone who loves you as you are

He's doing it out fear, not love.

To call him an control freak, and to say he's testing is to much in my opinion. (<--Other answers)

But you need to draw a line, you have already decided you want to wear those things, tell him one more time you are NOT going to change that, be clear about it.

You chose him as your partner, he chose you as his, he has no reason to fear others if you have no intention of pursuing others, he should already know this but it can't hurt to say it out loud (again).

Be clear and don't assume he knows what you know, this leads to uncertainty.
(Same goes for him of course)

If this still doesn't work you can try this:

Ask him what it is that makes him so uncomfortable with you wearing certain clothing.
I'm sure you will have a sound reply to all of his points (fears)

Good luck !

This is a serious red flag. He is testing you to see how much control he can take with you, and he has already succeeded in getting you to worry about what you wear. The next step is to shove or push you and see whether you'll worry about doing nothing to upset him. After that, he wants you to worry about setting him off by leaving him, so you will stay and accept whatever abuse he wants to dish out.
You don't need to talk to him. You need to run away from him, immediately, and then ask yourself how you allowed this relationship to happen. You have enough of a backbone to know that it's your body, your clothes. Figure out why you didn't stand up to him the very first time he told you how not to dress. Check your self-esteem hon. It can't be what it should be or you wouldn't be trying to "talk" to him and make this dangerous relationship work.
Best of luck.

He is too controlling. Dump him

He isn't doing this stuff "out of love", he's doing it because he's a control freak. I'd tell him if he doesn't like leggings, he doesn't need to wear them. and if he doesn't like some of his stomach showing, keep it covered... etc... and i'd also tell him to accept me as I am or move on.

He doesn't want guys checking you out? they are going to check you out whether you have leggings on or not.

The guy you are seeing is a bit dumb

wear what you want, if he don't like it you can get a lotta boyfriends who will

You just need to come out and say it. As him being your boyfriend you both should be really close. You should be able to wear whatever you want to wear. He's needs to understand that he's not your husband or your dad. Sit him down one day. Push all of your nerves out of the way and tell him exactly how you feel. He can't guess your feelings so you have to tell him. Gather up the words for it.