your dude being way to close with your cousin

Would y'all feel some type of way with your man being way to friendly with your female cousin like this started out know where he be tag her into post asking her to send him back some food or he will share his food with her shit like that I'm not feeling it y'all think I'm doing to much and it's crazy because they start getting close when we broke up but now we back together he still be talking to her like crazy