· jennifer garner made rare comments about her boyfriend john miller and what co-parenting with ex-husband ben affleck is like in a new interview with marie claire uk. · jennifer garner has had an off-again-on-again relationship with john miller since 2018, but their pairing doesn’t get as much attention compared to her ex-husband ben affleck’s short marriage. · while they remain close friends and co-parent their three children together, were here to set the record straight: In fact, the 13 going on 30 actress is still going strong with her boyfriend, john miller. John is basically living with jennifer, a source told usweekly in may, clarifying that. · from dating michael vartan to divorce with scott foley and ben affleck to currently dating john miller, heres a look into the relationship timeline of 13 going on 30 actress, jennifer garner. · jennifer garner and boyfriend john miller reach new high in their relationship after rumored tensions. · jennifer garner is sparking engagement rumors with boyfriend john miller after she was spotted with a glittering piece of jewelry on her ring finger. The two actors are not dating. Here’s everything to know about jennifer garner ’s boyfriend, john miller. · jennifer garner and her boyfriend john miller were first linked in 2018.