So, only by cruelly and constantly that someone could be a lesbian? And it is mind trick, darling. To make Filly see Rumble in pensexual way. See him as person not gender. Set him above the male and female. The third gender.
Thought, even if it is mind control. It is a mind control by choice, the victim asked for it herself. So what in you right to against what she want?
And like I said, there have a page limit. Just like an original cartoon itself that have air time. That why happiness seem to come too fast to your like. Or you want some song song that alway seem to solve all problem in Equstria?