As played, I think you HAVE to call. Bad spot for us when they are already ahead, but he should've shove preflop with 77s.
If I were you B vs B - I would have shoved preflop, we have 5bb and the guy limped into us - sure sometimes it's a trap but more often than not it is a sure sign of weakness and we can take the aggressive initiative and win the hand. In this particular scenario it plays out the same but I think you will find yourself winning more pots this way. Dont just go shoving any old hand - I'd say most of your mid range Qx+, JT+ all the Kx and Ax and all the pairs is probably ideal.