My experience as a top is that 50% of bottoms really adore being fingered, and the remaining 50% feel like you're pushing a chilli pepper in their hole.
Fingering has to be done slowly, looking for the right spot (the prostate, like if you're trying to touch his dick from inside) and with lots of lube. I see lots of tops who copy porn and push their finger inside roughly and fast, which just irritates the hole.