The current UK immigration rules are looking for applicants to prove - on the balance of probabilities - that their relationship is 'genuine and subsisting', which means real, and ongoing. Beyond that, it is not precisely defined as to what you must provide.
Our approach is that it is worth 'going large' to show your true love. This is because there isn't guidance the person deciding on your application can fall back on to assess the relationship requirement. So you need to make it abundantly clear.