This porn video tag can be broken down as follows:
1. "big" - Refers to the size of the penis, which is larger than average.
2. "cock" - Another term for a penis.
3. "ts" - Stands for "teen son". It implies that there might be a scene involving a teenage boy and his father/stepfather engaging in sexual activity with the same or different partner(s). This could be interpreted as taboo, incestuous, or step-family roleplay.
So, the tag "big-cock-ts" would typically refer to a video that features a man with a big penis (big cock) and possibly a scene involving a teenage boy and/or his father/stepfather engaging in sexual activity. This is for adult audiences only and may not be suitable for everyone.