Confused about this guy

I've been going on dates with this guy off and on for over a year now. We hangout for a while then we always stop talking (one reason being I started dating someone else). Well my ex of only 6 months and I broke up so we started talking again and have hung out a few times. He says he has super strong feelings for me but he says until we are officially a couple he doesn't care if I sleep with other people. I'm not doing that but he always puts it out there that he's fine with it if it happens. I asked him if that meant he's sleeping with other people as well and he said no that he's only interested in sleeping with me. So I guess my question is if he's ok with me hooking up with other men then there's no way he could actually have strong feelings for me, right? I can't imagine really really liking someone and just being ok with them fucking someone else. Opinions?