neeed advice bad. please read...

How the hell am I supposed to feel about this? Get this okay my boyfriend, every time we hangout with his brother EVERY TIME he questions me “what if he came on to you” “what would you do if he tried fucking you” all that shit. I understand cuz his brother tried fucking his ex gf so I get his insecurity but it’s getting old. So finally I snapped and was like this is ridiculous, how would you like it if I did this when we are hanging out with Jen (his brothers GF) and he was like that doesn’t matter whatever I let it go... fucking last night we get a knock on our door and I’m lol hm? And he’s like oh that’s probably Jen she asked if she could come over. As soon as she gets in she says how my boyfriend invited her over. Ok weird. Then she starts saying shit you just shouldn’t in front of someone else’s man about her boobs ass anything she could. And she leaves and I ask him like wtf you lied first off and then I asked so what would you do if she came on to you? He says he wouldn’t tell me first he would tell his brother “cuz his brother would deserve to know” BRO WTF she was flirting so bad with him and this is the first time ever I’ve had an issue like this in this relationship idk what to do or how to feel. Would you guys be upset???