Getting over someone

So I've been out of a relationship for a month now and we had sex and stuff but he still wanted to have sex and act like a couple after we broke up so we did but now we don't talk too much but I really wanna have sex with someone... I have one friend that wants to have sex with me but I don't know if that's okay? Like my ex and I last had sex two weeks ago and my friend wants to have sex either this week or next week... I really want to Coz I do like this guy but I don't know if that's considered moving on too fast?