Any known hentai video about nipple penetration? help pls

I'm 99% sure you're talking about Bondage Game ep 2. Can't say I know of any others, besides a game with animated cutscenes sort of like the Viper series whose name eludes me.

If you search the tag nipple_insertion on E-Hentai you'll get a lot of manga and CGs featuring that.

聖姦伝説リース by OZ
http://www.dlsite.com/maniax/work/=/product_id/RJ135075.html

I think dendendo does a few in his animations:
http://www.dlsite.com/maniax/circle/profile/=/maker_id/RG05045.html

Also, try using the proper keyword when searching:
ニプルファック (nipple fuck)

I now of only 2 hentai that have nipple penetration as well as a few dendendos. I will write them below, I hope they help on what you are looking for.

Buta no Gotoki Sanzoku ni Torawarete Shojo wo Ubawareru Kyonyuu Himekishi & Onna Senshi
Gakuen no Ikenie: Nagusami Mono to Kashita Kyonyuu Furyou Shoujo
Dendendou - Dead Sea
Dendendou - Busty Lady on Train
Dendendou - Sunburn