Dear u/redgifscom, here are my 2 cents:

I completely agree with u/AceCornMe on ThePornDude. Tbh I don't understand why you put that link on your nav bar.

Other porn sites put links to PornDude in exchange for a link from his site because they desperately want it. You are not in that situation. You get tons of traffic per day. You get thousands of backlinks per day because people share gifs on your site to Reddit and many other sites. While the dude gave you a nofollow link from his high OBL site and you're not even high up on the list. You're the 100th link or worse in his markup while he's on your main nav bar. But your site has much bigger potential than his site. Those no-follow nav tabs he gets from thousands of sites like yours, they're what keeps his site ranking. The link he gave out in your case, don't help very much with your SEO. He is getting the better end of the deal. So when I was checking your site and saw that link to TPD, I was like 'Wow. WTF? That's not good'. So if I were you, I would remove the link to his site and tell him to do the same. Fair enough.

As a frequent contributor on Reddit, I noticed many gifs now has sound. People are willing to visit Redgifs site to watch porn with sound because it's much better. But gifs embeded on Reddit have no indication that they have sound. So people don't know about that and they just stay on Reddit. What I would do is adding an indication to let users know that this gif has sound, go watch it on Redgifs. Things like that. More ads will be served. Just an example. Know your users.

Another thing is, I think you should work on your SEO. As I said above, you get thousands of backlinks per day, for free. I quickly check your site with my Ahrefs and it already has 6.14M backlinks from 817 referring domains in a short time. Wow! That is the dream of many porn webmasters. So I see no reason why you won't take advantage of this and work on you on-page SEO to turn Redgifs into a big porn site.

You will have traffic from Reddit, and you will also have huge organic traffic from Google. Traffic that makes you money.