what is the avarage bounce rate for tube sites, mine is:
 

Bounce Rate: 80.60%
Avg. Session Duration: 00:01:16
% New Sessions: 87.61%

this is for the last week, site has 13k daily and going up from all around the world.
niche: mainstream sex

what do you guys think?

It is a bad performance, here is some the biggest tube site:
Bounce Rate
23.90%
Daily Pageviews per Visitor
7.48
Daily Time on Site
10:02

You having a bad bounce rate.

Are you getting your bounce rate from Google Analytics? If so, check your referrals, see if your getting spammed.

Bounce Rate: 80.60% is very bad. You should try to make it under 40%. If you use wordpress, try related posts plugin!

I just started mine about 2 months ago and my bounce rate is 34.9% and average time on site is 1 minute 35 seconds.

You probably need to check for referral spam and make sure you filter those out.

steal more full length HD videos

this seems to be a common practice these days

Increasing number of related posts is very good strategy if your bounce is high. Also do not add more than one popup. Try to access your site from another device and check your loading speed. It may be also slow from other countries than yours depending on your hosting company.

But my sites are not so different:
Tubes
52,90 %
46,20 %
39,41 %
74,46 %

Blogs
67,71 %
66,04 %

I have around 40% on my blogs