I think you should bump this up on the flop. That way you can find out where you are (basically that you are getting beaten). On the turn there is $12 in pot and only costs u 1.5. I know that you're not closing action which is a problem but you're getting 8:1 on your money. I think that if you call and SB also calls (which i think he would bump it here with 77) you might be able to get a showdown for very cheap (maybe even free).