Here are some tips to make sharing a bed easier:
• If it is snoring that bothers your sleep, consider ear plugs, a sound machine, or some type of anti-snoring device.
• If it is their movement that bothers your sleep, consider a new mattress that reduces motion transfer.
• If they get up in the middle of the night and disturb you, consider two beds in the same room, or a mattress that reduces motion transfer.
• If they have a different schedule, consider scheduling changes, eye masks, book lights, etc.
Or, in the very least, opt for a bigger bed.