I am a P in UMP and, using miles, booked online for SAN-DEN for economy (E+). Pretty full flight. Gave my PNR to my girlfriend and sent her off to the local United office to buy a ticket for herself(discount economy). Told her to say 'this is my boyfriend, he is P,he gave me this PNR - can I sit beside him?. The agent had to make a phone call but within a minute she said 'yes' and we were both pre-assigned E+.