My son is dating 15 different girls at once

My son had been a legal adult for all of 2 months and got on a few dating apps. He's been going out nightly and today asked me for a favor. When I asked what said favor was he said "Would you mind telling 15 girls I'm dead?" I said he had about 15 seconds to explain. My son had been trying to casual date and he didn't want to hurt anyone's feeling so he always tried to reply to people who messaged him. Which has now left him casualing dating 15 different girls. I was upset and said "You know I didn't raise you to treat women that way." He said he wasn't trying to. He just didn't want to hurt anyone's feelings and thought if he didn't become exclusive with them then they would just move on but that hasn't been happening. I freaked out because I'm worried I'm gonna have 15 different grandchild and asked is he sleeping with all these women. He said "See that's the weird thing. I haven't had sex with any of these women and they still won't leave!" I told him he needs to just end things and he's like "Well that's awkward......" I told him I'm not telling women he's causally dating that he's dead. I asked which one did he like the most and just end things with the rest and he said "I don't know. I've lost track of who is is at this point and I have a date with one of them tonight and I just don't wanna date anymore." Fucking hell. Is this what having adult children is like? One minute you're changing diapers, the next you're in their dating life?

Edit: We talked about more and he's gonna try to tell them he just wants to be friends. Honestly it sounds like he was looking for friends more than a relationship anyway because it seemed he just wanted people to hang out with. Not have sex with. I kind of had to explain the difference between casual dating and simply wanting friends because while casual dating doesn't equal sex from what he wants it doesn't really sound like he wants a relationship.