Small transmission fluid leak from radiator transmission cooler line

[EvanVanVan]

I'm trying to decide what I should do, I've got a small transmission fluid leak from either the upper or lower transmission fluid cooler line as it goes into the radiator. I've tried tightening it very tight. While tightening the nut, I held back on the line with a small 6" pipe wrench. Both upper and lower are very tight.

This is a new problem since I replaced my radiator (with a Silla 2067A) and lines a couple months ago. I'm not even sure if it's the line/nut leaking or if it's the larger 1" hex nut that is part of the radiator. I can't warranty/return the radiator because the company ended up giving me refunding me fully for it after a mix up with the shipping.

I'm not sure if I should A. leave it go, and just check it once in a while and top off as necessary. B. Buy a new radiator and install it, again. Or C, but one of those secondary external radiator cooler things.

I mean it's like a REALLY SLOW leak, I've driven with it for 2 months and haven't noticed any real drop on the dipstick, yet every time I look/stick my hand down there it's wet () with pink fluid (underneath the air dam).