Kerkermeister,

Firstly: do
NOT put one connector on you and another on your partner, as this could send current through the heart area. Be sure that no current flows across the heart, as this can be dangerous. Keep all contact *below* the waist, unless you know what you are doing.
Perhaps ask
Jo about female connectors and sensitivity. She is knowledgeable:
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Is it the size of the insertable that makes you ogle? - If so, do not assume that bigger is necessarily better in eStim. Sometimes a smaller 'trode (without burning) can provide the most satisfying stimulation - for example with prostate stimulators such as an adapted 'Aneros' or similar.
By 'pain' I assume you mean 'sensitivity'. You can test 'trode positions and levels on low setting, to see how you like that, then gradually turn up, or let the machine turn itself up v e r y slowly.
You are right about anal sensitivity, but remember that we can also vary sensitivity very much with our
minds. If you do not feel anything at low level, pause and sense more closely. You may find that something is actually happening, when at first you did not at first feel this.
2mm loops can be a bit thin, unless you like a very localized effect. Perhaps begin with 4mm which is likely to feel more comfortable.
A 'clap' is unlikely to provide satisfying eStim. You can use the routines on your eStim box to deliver the 'clap', by selecting short-burst rhythmical wave patterns, or use similar
audio (e.g. mp3) routines that do this, through your eStim box. Short-burst patterns can be satisfying if you concentrate, and allow them to become enjoyable for you.
One fun technique is to find 'trode positions you like, and then change
very slowly from separate pulses to faster pulses to a continuous buzz. Play by varying this frequency from pulse to buzz and back.
Experiment slowly and safely. Listen to your body/bodies. Take your time. Play safely.