@pinkflameinthepan IMO it can be fine, but things to be careful about:
- Are they being normal about it or trying to hide it from eg. their partner
- Do they recognize the difference in life experience, and account for it
- Do they have a good understanding of consent (not just in words but also in actions)

Those aren't *really* specific to age differences, but they are a bit more critical with a big age gap because of the whole power differential thing