Should i believe in god to make others happy?

I've lost a girlfriend for being athiest, my own mother is a devout catholic, and any chance of me getting a decent girlfriend relies on me believing in something. For me, since i don't believe, it doesn't really matter that i go through the motions of "believing" if it'll make someone happy. essentially religious people are egomaniacal anyways sosaying i believe isn't going to make a shred of difference to me. Is this morally wrong to just say you believe in god when you really don't, just to make people happy?