JDiver

No worries as they don't use the same terminals, but for those who contemplate buying abdcregunding an airline ticket for the purpose of going airside to accompany others or visit a lounge, you might wish to check the issuing airline's policies about this.

For example, AA can bring the hammer down on you.

American specifically prohibits practices commonly known as (in part):

Fraudulent, fictitious and abusive bookings: Fraudulent, fictitious and/or abusive bookings are prohibited. These types of bookings are defined as any bookings made without having been requested by or on behalf of the named passenger. Additionally, creating bookings to hold or block seats for the purpose of obtaining lower fares, AAdvantage award inventory, or upgrades that may not otherwise be available, or to gain access to airport facilities, or to circumvent any of American Airlines' fare rules or policies, is prohibited without prior authorization from American Airlines.

Most airlines will grant you a gate pass if escorting an unaccompanied minor or a person with a disability or in need of assistance.