My boyfriend has been in jail for two weeks for a DUI. Apparently its his 5th one in 3 years. He is a permenent resident. Will marrying him now stop the possibility of deportation?

You are thinking of marrying a man who has had 5 DUI's in 3 years and never told you?

Yes, if he is determined to be a habitual offender he can be deported. Being married will not change that.