since there is absolutely nothing villain plays this way that you beat (i exclude an idiotic bluff since BB is almost 300BB deep and even a bluff shove is offering you nearly 10:1 odds), you can fold this.

I wouldn't have though of it at the time, but sauce's suggestion of checking the river is probably best since BB most likely holdings are two pairs/sets, since he called before knowing what UTG+1 was going to do.