baby not sleeping in crib

So
Hey mamas, so my baby has been in his crib since he was one month old. He's now approaching 4 mths next week and I've noticed that he cries and cries for his pacy in his crib but as soon as I pit him in my bed to co sleep bc I'm tired of getting up every 2 min to re enter his pacy he sleeps just fine, pacifier in mouth or not..
So my question is what's happening here? Does he prefer to co sleep and he knows mama will eventually give in to his rebellious ways? And any ideas on getting him back in his crib? Tia