MoJo
it seems highly unlikely to me that a man who doesn't suffer from ED could perform oral or manual on a woman to the point of orgasm and not become aroused himself unless he had recently ejaculated.
I read where one guy went soft giving oral because he was concentration on his W’s pleasure/reactions.

RJ
If a guy is struggling with ED issues/performance anxiety, wouldn't it be easier to work on intercourse from an on-top position or side position, rather than on bottom?

From what I have read and saw on TV sex programs, a guy cums fastest if he is standing upright and the female partner is laying on the edge of the bed. Some call it the Worrier position, others call it the furniture position, like here>http://www.sexual-health-resource.org/sex_positions.htm

Click on some of the alternative to the main positions for some animation.

Side position requires a long member or a strong erection.

For me bottom works well if BB spreads her legs and wants to position herself correctly. I can do almost all of the work and play with BB’s hair–back-butt, which are usually additional turn-ons for me in a tactile sense. Penile sensations are a little less when I am on the bottom because BB doesn’t position herself the way I like and she tends to not be very active.

Me being on top is best for me erection and penile pleasure wise.

Dom, I know Lil knows what she is talking about. I have read her posts for a long time.

Lou