The GIF under question is from MachoFucker, which has always been 'bareback', the top is Ivan, one of their most remunerative models (he embodies that "Macho"), and knowing how long and hard he fucks the bottom every time, when he's about to come he is tired and doesn't overdo it as some tend to do. He's also not affectionate but appears to be an all around nice guy. As for the "cum" splattering out, it could be lube as well. Those men are hung and the bottoms sure need their tubes well oiled. Also, many of their scenes are shot on the same day, and if a bottom had been used in two or three of them, a previous "internal" may had been possible, leading to the abnormal cum splatter in this particular moment.
From what I can gather in gay porn, fake cum is really only used in photoshoots. ManRoyale was under suspition of using a lot of fake cum in their promos shortly after their debut. It's certainly easier to do with posed set-ups, it's very hard to add it to an unscripted semi-pro amateur shoot with mainly new talent. The scenes are overshadowed with acrobatics and smart editing anyway. I can't speak for mainstream studios such as Falcon or Rascal from the scripted era, but everybody else seems to stick with what nature gave them, the content is very standard but it shouldn't surprise anyone that some men can produce a lot of cum (and I believe they are advised not to have sex or masturbate for a few days before a shoot). For the studios that rely on creampies or facial shots, you can clearly see they are real (or so they appear as they never seem to cut away.
As for bareback and internals, there are in fact two approaches to bareback, one is conventional 'bareback' (MachoFucker, BarebackThatHole, TreasureIslandMedia, etc.), which comes from the underground/private scene and includes regular internals, creampies or other games involving bodily fluids (Their models are also more the risk-takers as the scene is somewhat part of their private life). The other is going "condom-free" (
Bel Ami CorbinFisher,
Sean Cody, etc.), where the condom is left out for the sake of comfort and "realness" and/or editing and flow of the action (It appears less inexperienced models have trouble getting hard and the veterans can take it up a notch).
In both instances the men are tested beforehand and everyone is fully aware of each other's health status and has signed some form of NDA.
And last but not least; it is very well known that [gay] porn is the safest way possible to have safe bareback sex, more so than a monogamous relationship. Testing is vital not only for everone's health but mainly for legal reasons and to protect the studios assets. If an alleged gay for pay model has contracted HIV then it most likely happened while escorting and taking the risk of having unsafe sex with an untested stranger, and sometimes they get it from their female partner.