Yes, it most definitely can work long term, and the wider age gap relationships can be some of the most physically and emotionally rewarding. But, be warned, it will be hard work at times to keep it going. There is enough of an age difference that expectations about lifestyle and relationships are rather different, as well as the natural age factors.
The three main hurdles this sort of relationship will hit are:
- when the woman hits her late 40s and starts going through the change, while the man in question is still in his mid 30s and at his sexual peak. Sex pretty much drops off the radar during the change, which can cause huge problems.
- when the man hits his early 40s and starts eyeing up younger women again. The woman, being well into her 50s is going to feel very hurt and defenseless about this.
- retirement, should you two make it that far. That one can kick up a lot of resentment.
None of these hurdles is insurmountable. Just acknowledge they exist and that you had both better be ready for more honesty and compromise than other relationships may need.