I'm NOT forced to wear panties, and I've been wearing them long before I was ever a cuckold... But I can say (for me anyways) there's nothing more feminine than putting on a cute bra and sexy pair of panties. It's definitely a mindset for sure.
To wear a cute bra, my cock cage and a sexy pair of panties brings my sissy side into full bloom.
Lucky for me, my wife is more than happy to have me wear all 3, and fully accepts/embraces my Sissy side.