It could be that Mason and Alex are in a long - distance relationship. When Alex discovers she's pregnant, it throws their relationship into chaos. Mason has to decide whether to move closer to Alex or try to support her from afar. There could be a lot of drama as they try to make decisions about the pregnancy and their relationship.
For Mason, you can give him some flaws. Maybe he's a bit of a procrastinator at first, not really taking the pregnancy seriously. But as he sees Alex's determination, he changes. Alex could be developed as a very independent character. However, the pregnancy makes her realize she needs to rely on others sometimes. You can show this through her interactions with her friends and family.
One possible plot twist could be that it was an unexpected pregnancy. Maybe they were just starting their relationship and this news completely changes their plans. They might have to deal with reactions from their families and friends, some of whom could be very supportive while others might be shocked or disapproving.
Their relationship might become more intimate as they share this life - changing experience. They'll be more reliant on each other for emotional support.
The victim of the kidnapping could be a central character. Maybe it's a journalist who was about to expose a big story and Alex and Mason were hired to stop them, but as the story progresses, the journalist reveals the truth behind the people who hired Alex and Mason.
Adventure is also often seen. They might go on quests or explore new places together, which makes for exciting reading. For example, in some stories they are in a jungle exploring ancient ruins. This not only tests their physical strength but also their relationship. Another common theme is self - discovery. As they go through different situations, they learn more about themselves and each other.
Well, they might be into fanfiction about their favorite TV shows. For instance, if they are fans of 'Stranger Things', they could love the fan - made stories that expand on the show's universe.
Well, perhaps in this fanfiction, Alex and Mason kidnap a character who has some sort of special power or knowledge. They think they can use this person for their own gain. But during the time of the kidnapping, they find out that the person is more complex than they thought, and they start to form an unexpected bond with their captive.
Perhaps a character who has some valuable information. For example, a scientist who has just made a major discovery. Alex and Mason might kidnap the scientist to get the details of the discovery for themselves.