I'm going to go deep here for a sec... hear me out.
It seems to me that if they are already laughing...cha-ching! You still got it.
I wouldn't assume that they found you ridiculous- or pitiable. Women have odd ways of demonstrating admiration for men. On the other hand. those females might be nervous about your hypothetical potential as a partner and of course, a potential threat. A grown man, in his prime is pretty intimating to most women and they have developed numerous strategies to deal with a power disparity. Perhaps they were attempting to reduce the disparity and even negate it by laughing at a pheromone emitting male. It works to dissipate the obvious situation. A man in the presence of young and ovulating females. Think about how uncomplicated this would be to understand the situation with any other species of mammal. The fact that you are demonstrating your viability as a parent makes attraction but also makes nervous. Try to enjoy when women get nervous around you. It's a good thing. It's the power of being a human male in his prime. If you are happily married- so much the better. Limited time offer.
After that they are are no longer laughing when a man is perceived to be a harmless grandpa. Then, I suppose they feel that it's relatively safe to hang out with you. It's very nice to have females feel safe and they come in close again. That is enjoyable too.