On the Mat Day 72: Sweeping kneeling opponent

I have just relaxed this week since the competition. Eat what I like, sleep when I want, it's been great. I went to class last night expecting only a few people coming along. A young kid, high-school, who is very keen was the only one there. Arata-kun is his name. He is improving very well. Koyama-san asked me to be the demonstration partner which was a first for me. We did sweeps on opponents who are kneeling using an x-guard type move. I've seen these before so nothing new but good for a recap.

For the sparring, a white belt, blue and two purples turned up. The purples are two big dudes, must be over 100 kg but a mix of muscle and fat. They're still heavy. I sparred with them first but still ended up under side control. Really need to work on this but I can't really put a lot of effort into escaping because of my injury. The white belt, I kept putting into closed guard from standing with the exception of a standing sweep which sent him spinning to the ground. I want to practice jumping to guard, even though I'd not use it in a real fight, everyone does it in competition so I need to get a feel for it. I was suprised that the guy didn't try a more conventional closed guard escape but instead he went for a collar choke in closed guard. I can see it being effective for some people but there are better ways in my opinion and he needs to work on opening the guard so why does he attack when trapped in closed guard? I don't understand his logic. I think he is thinking less of self-improvement and more instead of getting that tap. I caught him in a kimura and then an armbar. He just would not tap though until I put the lock on. Usually if my arm is isolated I will not fight and instead tap. I think the guy is gonna get injured badly sometime. The blue belt watched me during this sparring and told me off for locking the guy's arm. I understand that and normally I wouldn't lock an armbar but I was a little angry that the white belt kneed me in the face without apologizing (something I always do) and he seems out to get me for some reason. I take the arm, before extending look at his face, see no reaction or willingness to tap, then I lock it. I saw the blue belt talk to him later, I think he was telling him that he should tap, because in competition he would get the arm pulled badly. Knowing when to tap seems an important part of BJJ.