Olivia O'Lovely

Was watching this film the other night and I noticed something I had not seen much before.
During Olivia's scene with and Anna Nova and John Dough it apeared as if, while Anna was riding John's dick, Olivia used one of her hands kind of like a cock ring. I know that playing with a guy's balls during a scene is commonplace, but she seemed to at first be deliberatly gripping the base of his cock quite hard, at one point just using her index finger and thumb to squeeze the base. She then wrapped her fairly long fingers around the entire base of his balls and his dick, just in the way that a cock ring that goes aroung the balls as well would do, and again appeared to be gripping quite tightly.
Like I said, this may not seem to unusual as 'ball stimulation' is very common, but this was noticably different to me.
Mr. Dough didn't appear to need any assistance during the scene though.

Only other times I've seen this sort of thing was in the Viv Thomas film 'Sex Analyst' starring British bombshell Sammy Jane. In one scene she plays a doctor who's patient suffers from premature ejaculation, a couple of times during the scene the guy claims he is about to come, both times Sammy Jane quickly grabs the base of his cock, telling him that if he needs to come, she will hold his dick by the base, stopping him from cumming.
In another scene she and another girl are sucking a guy off, preparing his dick for a bit of anal action. 'Grab his dick hard by the base' she tells the girl, 'look how hard its getting' shortly followed by 'his dick needs to be really hard before it can go up your ass.' Quite horny stuff really.

Anyway, just wondering if anyone else noticed this about Olivia's scene, or if anyone has seen similar practices in porn films?