Maybe they were being tongue-in-cheek? 
Seriously though, that’s just poor deportment. Straight or gay, “sloppy tongue sucking” should not be done in public. Unless you’re a model and/or a porn star. Or very drunk. Or have one hour to live due to an apocalyptic impact from a meteor. 
Public displays of affection in Taiwan? Not good form, as the locals don’t like it.
Unless it’s holding hands. And half the time there’s nothing sexual about it, as it’s usually just two girls walking down the streets with their best mates.
i find that even holding hands with my woman turns heads fast enough to snap necks!
of course, just walking down the street by myself turns heads 
just not as fast
Oh, I think a little kissie-poo is reasonable. Who cares what other people think? As long as you’re not getting frisky in front of the kiddies or your business partners, and you are willing to deal with the consequences, I say ignore social convention.
Yes, ignore social prudery, as it is wrong. There is nothing wrong with kissing in public places, or holding hands as u walk down the street. The Chinese culture must change and adapt. It is wrong to be prude. But teach them slowly. They will love it. Like zee French do…