Tomato Sideshoot help please

This is my first year growing tomatoes and I seem to have missed a few of the sideshoots, so some of the plants appear to have two growth points.
Do I
a) pinch out regardless even though there are flowers forming
b) pinch out the tip of one to try and stop further growth
c) let them carry on and see what happens?

To get them off to a good start I shoved some well rotted farmyard muck into each bucket (about a third), so the leaves went mad. Lots of flowers forming but no fruit yet, they are about 2 foot tall and in an unheated greenhouse.

Thanks for that, seems like I'l have to get stuck in with a sharp knife.  I always feel cruel having to curb anything that's havng a good go at growing.