First of all finding someone else is not always the answer.  Try talking to him, and see what he says.  It could just be that he doesn't know or it could be age.  But guys cant fix anything if they dont realize something is wrong point it out, in a way not to hurt his feelings.
i,m 20 and my boyfriend for almost 3yrs is 30 and his sex is starting to get kind of dry,what should i do.?